


Mei and Mercy's Weatherproofing Weight Gain

by DudeManWriter



Category: Overwatch (Video Game)
Genre: Gen, Stuffing, Weight Gain
Language: English
Status: Completed
Published: 2020-07-01
Updated: 2020-07-01
Packaged: 2021-03-04 22:08:46
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,074
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25023706
Author URL: https://archiveofourown.org/users/DudeManWriter/pseuds/DudeManWriter
Summary: Mei and Mercy discover a secret bio-mod that Moira had been working on back in her Overwatch days, but they could not have expected this to happen.
Kudos: 7





	Mei and Mercy's Weatherproofing Weight Gain

It was a gloomy old day at Watchpoint: Gibraltar, made gloomier by how few people were there. Most people were still on holiday from Christmas, as it was only a few days past New Years. Among the few people who were there was Angela Ziegler, or Mercy as she was commonly called, and like most of the people who were there, she was busy working on something, her workaholic tendencies winning out over what little desire Mercy had to rest and relax. The most ‘relaxed’ she was on this day was dressing slightly more casually than usual, with a parchment coloured blouse and dark capris. She had her head down at her computer, going over her research for the umpteenth time, when she heard a knock at her door.

“Come in!” she called out, her eyes not leaving her computer’s holographic screen. Through the door stepped Mei-Ling Zhou, although she preferred to just be called Mei. She was overdressed as usual in her thick blue and white jacket, although at least it was winter, at least she wasn't somewhere hotter.

“Hi, sorry to bother you Angela. I wanted to ask you about something,” Mei asked sheepishly, bowing her head slightly in greeting.

“Oh, Mei, hello,” Mercy said, more cheerily and actually looking up from her computer for a moment. “Sorry, I was just working on something. Although, looking at the time, I think it would be best if I have a break.” She leant back from her computer, stretching her arms up above her head. “So, what did you want to ask?”

“Um... how familiar are you with Dr. O'Deorain’s work? The work she did while she was with Overwatch?” Mei queried, wincing slightly, expecting a bad response. Mercy let out an annoyed sigh.

“I know more about Moira’s work than I would like to. I’m not sure if I want to think about what she is doing over in Oasis,” Mercy complained.

“Oh, this is actually about something she recently announced,” Mei mentioned, as she watched Mercy visibly deflate.

“Something that will end up in Talon’s hands, I presume,” Mercy groaned.

“I don’t think that will be the case,” Mei replied, making Mercy perk up again. “I’m not even sure if Overwatch would be interested in it, but I think it would be very useful for me and my research.” Mercy raised a quizzical eyebrow, before quickly searching something on her computer.

“Hmm, what has she done now?” Mercy rhetorically asked, her curiosity clearly piqued. It took only the briefest of searches for her to get her answer. This particular manufactured genetic miracle involved body fat and the ability to build it up. According to the articles Mercy could find, this bio-mod allowed someone to build fat extremely quickly, and that fat would be an unparalleled insulator. Mercy may not have had even a fraction of Moira’s knowledge on genetics, but she knew a thing or two about research and development. “She must have been working on that while she was at Overwatch,” Mercy thought out loud.

“That’s what I thought. Do you think any of it would be in the storage here?” Mei asked.

“Wouldn’t you be better off going to Oasis to do it?” Mercy asked back. Mei let out a nervous laugh and scratched the back of her neck.

“Eheh, she scares me a little bit, and you don’t,” Mei admitted. Mercy couldn't help but let out a quiet chuckle.

“That does sound like the correct response to her,” Mercy joked as she slowly got up from her seat, stretching as she rose. “Perhaps we should see if it is still here.”

With that, Mercy led Mei off towards the cold storage, where Moira’s confiscated work would most likely be. It didn't take long for Mercy to remember that the name was very literal, as it was almost freezing in there even before entering the actual freezers, and Mercy was severely underdressed, while Mei in her coat was doing just fine.

“Okay, I think it should be in here,” Mercy declared, opening one of the doors near the far end of the massive freezer. It took a bit of effort, as the door had iced over somewhat. Mercy was quietly a little bit embarrassed that something like this had just been forgotten about for so long. Leaving the door open, in the hopes that the pair didn't get stuck inside, Mercy and Mei slowly approached the various racks of vials. “Oh dear, this is a lot to work through,” Mercy worried, trying to see if any of them had anything easily identifiable on them. As she searched, she failed to notice that her and Mei’s body heat and the comparative warmth from outside was radiating into the previously freezing cold room. It didn't take long, but eventually the vials had thawed out, and quicker than anyone could have anticipated, the contents let out a puff of gas that filled the room concerningly quickly. “Mei, we need to leave,” Mercy ordered. Mei was out of the freezer and dashing for the exit of the cold storage in the blink of an eye, with Mercy shortly behind her.

“Are you okay Dr. Ziegler?” Mei asked, as Mercy caught her breath.

“I hope so. I don’t know if I was exposed or not,” Mercy answered. A few seconds later, her stomach rumbled, loud enough for Mei to hear, though not loud enough to drown out Mei’s stomach as it began to rumble too.

“We should get something to eat, I’m starving,” Mei said as she turned to head back down the hallway towards the rest of the base.

“Hmm, strange,” Mercy commented as she put her hand over her rumbling stomach. She shouldn't have been that hungry, or at least she didn't think it had been that long since she last ate. And with Mei becoming hungry at the same time, it was clear that this had something to do with that gas. Still, knowing that didn't stop her from feeling just so hungry. So hungry, in fact, that she didn't even notice as she entered the mess hall and unconsciously steered herself toward Mei’s table, which was almost literally covered in food. “Uh, Mei, that’s a lot of food,” Mercy commented, a good part of her just wanting to dig right into that stack of food. Mei blinked, and then looked down at the food, her eyes bugging wide open in surprise.

“Oh, sorry, sorry, I’m sorry, I didn’t realise I had so much food,” Mei quickly apologised, before her gaze softened and her eyes went a touch glassy. “I am very hungry though...” With a moment of staring at the food, the pair snatched at the mountain of food, beginning to plow their way through it like women possessed. They ate with just their hands, even when some of this food was very clearly not meant to be eaten with their hands, the women were just too hungry to care. They were running entirely on autopilot, barely even stopping to breath. The first real break either of them had was when Mei opened her jacket. If either of them were paying attention, or if Mercy even paused for a moment, they would have noticed how snug the blue long-sleeved top Mei was wearing was getting. It was being pushed up by a belly that was starting to develop a roll of fat, and strained even further by breasts that were starting to try and force their way out of the sports bra they were still barely packed into. Mei’s tights were only faring better because of their elasticity, but there was still a lot for them to contain. Meanwhile, Mercy was packing on her own weight, most of it ending up on a round, fat gut that strained the buttons of her blouse, with patches of pale fat peeking through the gaps. She instinctively undid the belt on her capris with one hand while the other kept shovelling food into her mouth. Then, all of a sudden, there was a snap and a ping that snapped the pair out of their eating trance. Mercy and Mei froze, before very slowly looking down at Mercy’s shirt. One of the buttons on her chest had popped, revealing a lacy pale gold bra that Mercy’s breasts were spilling out of.

“Oh dear,” was all that the mortified Mercy could get out, before, one by one, the rest of her buttons gave out, flying across the fortunately deserted mess hall. Her fat gut, spilling over her belt on all sides, was on full display, and Mercy was lucky that it was only Mei that could see her, and that Mei was in a similar situation. It took a second for Mercy to fully comprehend what just happened, but when she did, her face went bright red. She tugged as hard as she could on her shirt to try and cover herself up. 

“Angela, do you… want my jacket?” Mei offered, her voice somewhat muffled by the food in her mouth, as she awkwardly tried to slip out of her jacket.

“Th-thank you, Mei,” Mercy said quietly as she slipped into the jacket. Mei might have been a bit bigger than Mercy, but not even that made this jacket a comfortable fit. Still, it covered Mercy up, as that was all she needed. “I, um, I think I’m going to go back to my office,” Mercy added, carefully standing up from her seat, a little unsteady as she adjusted to her new size.

“Oh, okay. I’ll be here if you need me. I’m still very hungry,” Mei said as she kept eating. Mercy also felt very hungry, but for her own sake, she knew that she had to try to push through that and get back to her office.

\---

Not too long after the pair were exposed to the bio-mod, Mei disappeared in order to ‘prepare for her return to the Antarctic’, which meant eating unfathomable amounts of food in order for the weatherproofing weight gain to fully take place. That left Mercy at Gibraltar, dealing with the effects on her own. She made the decision to get ahead of any possible rumours and made an announcement to the rest of Overwatch, alerting them to what had happened to her and what was going to happen to her. Namely, that she was going to get fat, incredibly fat.

And get fat she did, despite her best efforts to attempt to exercise and moderate her food intake. Unfortunately, her job didn’t leave her much time to exercise, so that was a bust, and any attempts at eating a reasonable amount of food were immediately and inadvertently undone by Mercy feeling so hungry that she needed more and more, until she was stuffing mountains of food into her mouth at almost every meal. By the end of the month, Mercy was truly massive. Her belly was the size of a yoga ball, although it was only ever the shape of a yoga ball when Mercy ate particularly large meals, which was actually fairly often, Mercy realised when she took the time to think about it. Of course, that wasn't all about her that got big. Her chest rocketed through cup sizes, reaching the size of basketballs and being a real pain to get bras for, meaning that Mercy had to rely on custom-made bras that usually only lasted a few days before needing to be replaced, and only a few days more before they would completely give out on her. Her hips widened out dramatically, leading to her needing a specially made hovering chair in order for her to not get stuck. Sure, she still spilled over the edges, but that was far, far better than being uncomfortably wedged between chair arms and trapped by her own size. Along with the wider hips came a much larger rear, each cheek like a beach ball in size and shape, which helped in making her chair much more comfortable by bringing her own extra padding, while making things more difficult for her by needing some outrageously large pants.

It wasn't just her clothes that needed changing due to her size. Her whole working style had to be changed to accommodate her new size. Her size was more of a hazard in the lab than she deemed acceptable, and so her work started being much less of a practical nature, with her being parked behind a desk with theoretical research, along with the massive amounts of administration and paperwork involved in running such an operation. Her office, where she spent most of her time nowadays, also needed significant changes to accommodate her. Starting with the door to enter her office, that needed to be widened to a double door. Although, to be more accurate, such a change wasn't strictly needed at that point, as she could fit through the single door with a bit of careful manoeuvring, but Mercy knew that eventually not even the most careful of manoeuvres would get her through the door, so the pre-emptive measures seemed like a wise decision. Moving to her desk, a few changes were made. Firstly, it was replaced with one that was a sort of horseshoe shape, with the middle of the desk, which faced the door being the part with the computer built into it, while the sides had large amounts of storage built in. This was important, as after being exposed to the bio-mod, Mercy was just always so hungry, and so having lots of places to store food was important. A hungry Mercy was an unproductive Mercy, she very quickly realised. The computer was also special in that it had a holographic keyboard, one that could be rearranged where ever Mercy wanted it to be set up. This meant that, no matter how large Mercy got, she would always be able to work. She had briefly considered having a voice control set up for her new computer, but those voice controls always seemed to have issues with her accent, and they were not particularly useful when her mouth was full, which it quite often was. In addition to those changes, she had a special two-way intercom system that she could use to contact the lab, and that the people in the lab could use to contact her. Even if she couldn't be in the lab any more, she was still going to be able to stay up to date and informed on what was going on down there, which included research into counteracting the bio-mod that was affecting her and Mei.

\---

At the end of the month, Lena ‘Tracer’ Oxton returned to the base after a month off that she had spent at home with her girlfriend, Emily. She went around the base, greeting everyone and catching up, before her path through the base took her past Mercy’s new office.

“Oh no, I forgot, she sent me an announcement about something. What was that about?” Tracer asked herself as she fished her datapad out of her jacket pocket. She went searching for the message, but no matter where she looked, she wasn't able to find it. “Ah well, she’s here, I can ask her myself.” Tracer then went to knock on the door to Mercy’s office. “Blimey, this is a big door,” she commented to herself, before speaking up to talk to Mercy on the other side. Angela, I’m baaaa…” Tracer’s voice faded off, not at all prepared for what she saw, her face going a little bit red. Mercy froze, half a donut mostly stuffed into her mouth. Slowly, Mercy chewed and swallowed, before awkwardly speaking up.

“Oh dear, Lena, I’m sorry. I forgot that no one had mentioned this to you yet. This,” Mercy said, gesturing to herself, “was what the announcement was about.” There was an incredibly awkward pause as neither person was entirely sure how to bring up the elephant in the room. 

“So, uh, how is Emily?” Mercy asked, trying to break the ice.

“Oh, uh, yeah, she’s good, she’s… uh… wow. Sorry, this is just… kind of a lot to take in at once,” Tracer eventually got out, despite how flustered she was. “What the bloody hell happened to you?”

“Ah, it was a mishap with one of Dr. O'Deorain’s experiments that had been locked up here. Dr Zhou thought it would help her with her research, we got distracted, one thing led to another and now I weigh more than everyone else here, except for Winston,” Mercy explained.

“Right, right, yeah, I gotcha.” Then, a thought came to Tracer. “Hang on a tick. Moira’s thing was genetics, yeah? What’s Mei doing that she needs Moira’s stuff for?”

“She found out about a bio-modification that O'Deorain had developed here, one that would help her adapt to the cold temperatures she deals with.” Mercy then tugged on the collar of her tank top. “Speaking of the temperature, Lena, could you please open that window for me? Goodness, it is warm today.” Tracer raised an eyebrow at Mercy’s comment.

“It’s not that warm, is it?” Tracer asked. “I mean, yeah, it’s warmer here than it was back in London, but we get, like, one nice week a year, and that week’s definitely not in the middle of January. But yeah, I know what warm is, and this isn’t it.”

“I suppose it is evidence that the bio-modification works. Perhaps too well,” Mercy commented, the last addition turning into a quiet, annoyed grumble.

“Heh, yeah, too right,” Tracer said, filling the quiet air as she opened the window. “So, uh, what happened to the bio-mod thingy?”

“Do not worry, it is locked back up in the cold storage where Dr. Zhou and I found it. We also labelled it, so you should be able to avoid it,” Mercy reassured.

“Right, gotcha, good to know where it is, so that I can definitely avoid it,” Tracer said. If Mercy wasn't so distracted by all the heat, or at least how warm she was, she would have noticed the blatantly obvious shifty tone in Tracer’s voice, but that flew right over Mercy’s head. 

“Hey, uh, I just remembered, I gotta go give Emily a bell, let her know I got here safe. I’ll see you around!” With that, Tracer zipped out the door, fortunately closing the door behind her, so that Mercy didn't have to heave herself out of her chair to close it. It also made her room that much more private, so that she was comfortable enough to make herself more comfortable. She shoved her tank top’s hem up to let her big, blubbery belly be free and bare, to help her cool off better. With how snug her pants were getting, she also felt comfortable enough to unbutton them. In times like this, times that were getting very common ever since she had been affected by the bio-mod, she was very glad that she had her very own private office, and some very capable people to do the practical work that she wasn't as capable of at her new size. She finished off the donut that Tracer had interrupted, before making a start on the remaining six. That should be enough to tide her over until dinner in about an hour.

A few minutes later, Mercy had finished that box of donuts, and was strongly considering having another box. After all, she was almost always hungry, would another dozen donuts really ruin her appetite for dinner? Just as she was about to move her chair over to her donut stash, her console began to ring. Quickly, Mercy covered her belly back up. She ignored her undone pants, as the chances of her managing to do them back up quickly were slim, mainly because she was far from slim. Looking at her console, she realised that the call was from Mei. Tidying up might have been a touch overkill, considering what state she assumed Mei would have been in. Mercy tapped the button on the console to answer the call, bringing up a holographic display showing Mei in her office. It had been a while since she last saw Mei, and considering how much of a big eater she had become before she went back to Antarctica she expected Mei to be massive. In what was quite a shock to Mercy, Mei actually turned out to be a bit smaller than her. Make no mistake, Mei was a very large woman, but apparently Mercy’s more sedentary lifestyle and work methods had turned Mercy into an enormous flabby woman, while Mei had more of a barrel-like body, with not all that much flab or jiggle to her compared to Mercy. Mei’s body shape had a more even width to it than Mercy’s, with nothing jutting out quite as much as Mercy’s chest, or her belly, or her rear, or her hips. Still, Mei was big enough that her chair, much like Mercy’s, didn't have arms, nor was it wide enough to fit her. Her round face lit up as Mei saw Mercy, a smile quickly spreading across her soft features.

“Hello, hi Doctor Ziegler! I have excellent news!” Mei cheered. “The modifications have worked better than I hoped. I can handle the cold temperatures here so much better now!”

“Ah, yes, I can see that,” Mercy noted, seeing that Mei had swapped her usual long sleeved shirt for a sleeveless tank top. Considering how large Mei’s arms were, that was probably a very smart move on her part. However, the rest of the tank top was just about skin-tight on her, showing that Mei was probably in need of a larger size in her next resupply. “I’ve been feeling a lot warmer too as of late.”

“Well, I won’t need the antidote to the modification. I’m going to keep this,” Mei announced. 

“Have you been able to make the antidote for yourself yet?” Mercy let out a sigh as she sunk unto her chair.

“Nein, nein, not yet,” Mercy answered, the disappointment clear in her voice. “I cannot work in the lab at this size,” she explained, gesturing at her massive everything, “and the other people working for me have so much work to do. I cannot possibly ask them to stop that and deal with me.”

“Oh dear,” Mei said sympathetically. “If you ever want to work somewhere colder, you are always welcome to join me here,” she offered. “Hopefully they are able to bring enough food for the two of us. I have to eat so much to keep this body,” she added, patting her stomach, which then rumbled in response, loud enough for Mercy to hear it on her end of the line. “Oh dear, sorry, sorry, I think I need to go and eat. It has been very good to speak with you again. Good bye!” With that, Mercy said her farewells too and the call ended, leaving Mercy again alone in her office. She had to admit, Mei’s offer was tempting. A chance to get away from this verdammt heat would be wonderful, and she wouldn't constantly have the feeling that she was being judged or pitied for her weight. After all, Mei had nothing but nice things to say about her own weight, surely that would also be the case for Mercy’s weight. Still, there was a part of Mercy that did want to go back to her old size and be able to go out on missions to help people. And even if that part was ignored and Mercy did stay her new, increased and steadily increasing size, she did like the food she was able to get here in Gibraltar, although she was still unsure whether it was the quality or the quantity that she liked. Also, moving to Antarctica would mean that she would be so very far away from everyone else at Overwatch. There would be constant calls keeping her up to date with what was happening at the labs, and on the rare occasion that she felt the desire to, she wouldn't be able to waddle down to the lab if she was all the way down in Antarctica. Clearly, she would have to think on Mei’s offer for a while, make sure she really was sure about what she wanted. In the meantime, there was another box of donuts that needed to be dealt with.

**Author's Note:**

> This fic was for Kamenmaster over on DeviantArt.


End file.
